Well, first of all, if you don’t want to take a gap year at all remember that programs will never SEE your senior year grades. If you are planning to graduate in May 2016 and start a psychology program in September 2016, that means you’d have to apply for master’s programs this fall - between November 2015 and maybe early February 2015. If your application deadlines are primarily in December and early January, as most of them are, your programs won’t see your new senior year grades. They’ll only see what you have done so far, ad frankly, your chances of getting into any master’s program are slim to none - even a for-profit program (unless it’s the kind that simply takes your money regardless of how you do, but you don’t want one of those). So I think you pretty much have to take a gap year, at least.
Secondly, why would you assume/predict that you will get straight As if until now your performance has been primarily Bs and Cs? It would be great if you did, but I think when predicting your potential GPA you need to be realistic because it lets you plan better. In fact, consider a range of possibilities. What will your GPA look like if you get mostly Bs and a few As, or a mix of As and Bs? I find it far more likely that your GPA will be somewhere between a 3.1 and a 3.25, and that your psychology GPA might be between a 2.5 and a 3.0 (maybe like 2.7, if you do well).
That said, even if you did get a 3.0 in your psychology classes, that is just barely scraping up the stated minimums for most programs. And many programs are quite competitive, so just because you have the minimum doesn’t mean that you will get accepted. I think that your chances even for Spring 2017 are pretty low; even if you did fantastically next year.
You need to take some time between undergrad and grad. You can take a few graduate-level psychology classes to show that you can excel at graduate work, and you can work in a counseling-related position for a year or two to show your interest and give you something else compelling to put on your CV. Your record needs to be otherwise outstanding to make up for the low GPA. (High GRE scores don’t make up for a low GPA - they can help, but the whole rest of the package needs to be excellent.)
Final thoughts. Most master’s programs in psychology actually will not allow you to practice counseling. You have to make sure that you 1) live in or plan to move to a state that licenses master’s level counselors to practice therapy, and 2) go to a program that leads to licensure in the state in which you live in. The last part is very important! There are many master’s programs in clinical psychology, for example, whose purpose is to prepare students for PhD programs in clinical psychology and they do NOT offer a path to licensure.
In fact, the master’s programs that offer a path to licensure often aren’t called psychology at all - they’re called “mental health counseling.” The main webpage will tell you whether it does.